AudioAficionado.org - New Tape Deck Manufacture

German translation of the M 063 -- seriously good:

The M 063 has been developed for the professional user as well as for the ambitious music lover. It features a highly dynamic three-motor drive and an ultralinear, low-noise amplifier technology with minimal distortion. Also new is the design of the torsionally stiff aluminum chassis: it has been led out on the back by 25 mm and serves as a stable support surface for horizontal operation. In order to ensure easy cable management, the connection terminal is offset by a further 25 mm inwards. In addition, the clear design of the back allows clear space in the room. The machine can be operated with up to 38 centimeters of tape speed per second and has a high-resolution, digital counter with all the associated functions. It can be operated with open coils of up to 30 cm and can be integrated in every 19 inch studio rack.

The clear front design with the exemplary usability is due to the strict adherence to a design grid. All items for recording are on the right and for playback on the left. The drive functions are centrally located. Due to the flat front the insertion of the tape itself can be carried out without a hand: the belt path around the rollers is self-explanatory and the pinch roller can be lowered by pressing the stop button once. The stop button applies to all drive functions and extends over the entire area of the keypad. Below is the setting control for the editing function: If this is switched on, winding motors and playback amplifiers are active. Thus, the tape can be transported precisely or manually by hand or by capstan motor, before or back.

The precise digital counter is a useful addition: it is driven by a high-resolution rotary encoder and counts the elapsed time in hours, minutes, seconds and hundredths of a second. The counter reading is coupled to the selected speed and is halved or doubled during switching to 9.5 cm / s or 38 cm / s. For this purpose, the counter is driven without impulse losses.

The intelligent, processor-controlled drive control prevents any kind of loop formation and tape stretching. Thus, even the braking process takes place from the fast winding operation, including the sensitive strip tension sensors. It is possible to choose between two tacho-controlled winding speeds plus the archive winding function with increased counter-pull. For this purpose, very torque-resistant and powerful engines with modern power electronics have been developed. Even at high loads, the reaction speed servomotors produce hardly any waste heat and run almost noiseless.

The low-noise audio electronics consists of a plug-in card system with very short signal paths. Recording and playback amplifiers are completely discreet. When recording, the equalization is carried out according to CCIR, and between CCIR and NAB can be selected during playback. The playback and recording electronics as well as the erasing oscillator are supplied with high-quality screening by separate power supplies. A power supply unit with ring core transformers and the spatial separation of audio and power electronics guarantee the high external voltage separation of the audio signal of at least 70 dB. Thus the playback head does not require any mechanically complex shielding. The balanced output signals can be adjusted from -10 dB to + 25 dB.

The front panel together with the audio unit can be folded out. Thus, work such as measuring to other bands or the replacement of individual amplifier cards can be performed from both sides. In addition, the setting controls are arranged on the amplifier cards so that they can be reached both from the front and from the rear. Therefore, if the machine is mounted firmly in a rack or in a console, it must not be removed for calibration. It is enough to remove the front panel. For this purpose, the control knobs are not placed on the front plate from the outside, but are passed through and can remain on the control axes. Likewise, the rear panel terminal was constructed: After the rear housing cover has been removed, it can be tilted horizontally downwards. The service friendliness was thus again increased.

The long-term stable chassis of the M 063 is made exclusively of high-alloy aluminum.

The base plate as frame parts are cut from the solid at low temperature and precisely machined in a CNC process. In addition, the cover surfaces of the base plate are milled on both sides, so that all mechanical elements of the belt run exactly and sustainably in angle and height. The head block and sound heads are manufactured so precisely that a time-intensive and inaccurate balancing of the sound heads is no longer necessary.

At low weight, the open frame construction ensures a very high long-term mechanical stability. The modules winding motors, capstan motor, power supply unit and audio unit are arranged in such a way that the signal paths are kept short, but the interference-critical components are spatially separated from each other. In this way, extensive measures for the electromagnetic shielding of the components, in particular the motors and the sound heads, could be avoided in advance. Cable management is also exemplary: All modules and circuit cards are equipped with high-quality plug connectors on both sides and, if required, with releasable strain relief. Longer cables and signal lines are combined in a closed cable channel with magnetic shielding. This allows service work to be carried out on all components within a very short time without having to change adjacent cables or components in position.

Central element of professional belting machine is the drive. For the M 063, all motors are located directly on the drive axles. With a maximum power of 65 watts, the capstan motor provides the fifth power that would actually be necessary for this application. Thus, the capstan can stand still in standby or winding mode and can be accelerated to speed. For a gentle and easy-to-start start, the pressure roller is first approached and then the motor is accelerated by means of ramp control.

When the nominal speed is reached and the tape transport is stable, the audio channels are enabled by the processor. This takes place at medium speed in 0.3 seconds. The speed control of the capstan motor is realized by the phase lock loop (PLL), which has been tried and tested for decades. A so-called phase comparator synchronizes the frequency from the tachogenerator of the capstan shaft in the microsecond range with a reference value supplied from the outside. In contrast to the tried-and-tested PLL control, the capstan motor of the M 063 operates with a frequency of up to 64000 Hz instead of a maximum of 1000 Hz. With this high sampling rate, the piano strength of this drive could be brought to a level that is normally only concepts with permanent Running capstan shaft and high inertia.

The brushless DC winding motors develop a very high and uniform torque with their axial magnetic field. On the rotor there are very compact and light high-performance magnets made of neodymium. Opposite, between the windings, ratiometric Hall sensors are arranged, which precisely detect the rotor position and transmit this to the processor. By supplying further parameters, this then determines the precise current of the individual windings, which leads to a very homogeneous run-out. Thus the motors of the M 063 deliver an evenly uniform torque even at below zero revolutions or negative speed. Two high-precision force sensors on the deflection pulleys monitor the belt tension and adjust the current of the winding motors without delay. This allows both a very uniform tape-to-head contact and a very low slippage at the pressure roller with a simultaneously low pressure force.

The machine has both a mechanical braking system and an electrical braking system. Braking from the winding operation takes place with the inclusion of the two belt tension sensors which guarantees a fast stop without belt stretching. The mechanical brakes are actuated by a stepping motor and hold themselves automatically in position. The servo drive of the pressure roller also behaves as follows: When the position or pressing force of the pressure roller is reached, the servo motor is switched off. The absence of tension magnets during the development of the drive ensures low noise and low power consumption. This allowed the heat generation of the machine to be reduced to a minimum and a power consumption of, for example, just 24 watts in playback mode.

Combined with the intelligent drive control, these components ensure a tape-friendly handling without power peaks and loops, while maintaining high dynamics and short access times at all times. To enable operation in a 9-inch rack, the wood side parts and feet can be removed with a few hand movements. It is not necessary to install additional rack brackets, the mounting brackets and bores are already on the housing.

Processor-controlled and directly driven 3-motor drive with 1/4 "tape drive and 2 channels

Winding motors: 2 brushless DC disk rotor motors with field-oriented sinus commutation. Electric brakes, controlled by tape tension sensors.

Capstan motor: 1 brushless DC disc rotor motor with field-oriented sinus commutation. Speed control by means of high-frequency PLL (phase locked loop), theoretical acceleration time at 19 cm / s: 0.08 s

3 stepping motors for mechanical brake and head block

Pressure roller driven via servo drive

Operating hours counter optional

Operating position Any between horizontal and vertical
Belt runner ball bearing left and right of the head block, one belt bucket roller left and right, damping element with deflection roller left and right outside. Head block driven for variable band head contact during playback and recording.

Belt speeds

9.5 cm / sec, 19 cm / sec, and 38 cm / sec
Tolerance of nominal speed: 0.05%

Variable speed: +/- 10% at 9.5, 19 and 38 cm / s

Variable speed for editing: -125 cm / s to 125 cm / s

Pitch variations> 0.04%
Hatching> 0.08%

Wrapping size Up to a maximum of 30 cm open wrap, fastened by means of screw clamps

Winding time
2 speeds adjustable: 5 m / s, 10 m / s
Small speed for archive wrapping at increased counter-pull

Drive control

9 microprocessors, 2 pressure sensors for belt tensioning, 3 speed sensors on winding motors and deflection pulley.

Remote control with infrared remote control

Real-time counter in time format Std / Min / Sec, 100 / sec, Autolocator function

Automatic threading to start of tape, autostop can be switched off during play and winding, automatic repeat function programmable

Audio electronics

One main board for recording and playback, All amplifiers as well as erase oscillator on separate plug-in cards. Headphone amplifier can be controlled and remote controlled via motor potentiometer.

Tonköpfe 3 Tonkopf- erenthekopf, writing head, playback head in 2- channel with 2 mm separating track. Full track extinguishing head optional

Equalizer Playback

9.5 cm / s: NAB 90 -3180 μs, CCIR 130 μs
19 cm / s: NAB 90 -3180 μs, CCIR 70 μs
38 cm / s: NAB 90 -3180 μs, CCIR 35 μs

Equalization recording

9.5 cm / sec: CCIR 130 μs
19 cm / s: CCIR 70 μs
38 cm / s: CCIR 35 μs

Frequency response (measured with Pyral SM 911)

9.5 cm / s: 30 Hz - 16000 Hz +/- 2 dB
19 cm / s: 30 Hz - 20000 Hz +/- 2 dB
38 cm / s: 30 Hz - 22000 Hz +/- 2 dB

VU meter 35 mm x 60 mm according to ASA standard, advance 1,5%
Distortion factor (measured by band) At 0 VU <0.3%
Noise level> 70 dB at band flow 1020 nWb / m at 19 cm / s
Surprising attenuation> 43 dB at 1000 Hz
Deadening attenuation> 75 dB at 1000 Hz, 19 cm / s

Inputs

Inputs symmetrical to XLR or switchable to unbalanced to RCA, calibrated switchable to uncalibrated +6 dB via setting controller

One large controller for input sensitivity per channel + one master with tandempotentiometer 2-channel

Outputs

Outputs symmetrical to XLR via spindle dimmer -10 dB to + 25 dB adjustable + unbalanced to RCA, calibrated switchable to uncalibrated +12 dB via setting controller

In addition an unbalanced output on RCA with level control via motor potentiometer with infrared remote control

Power supply 240V AC via 3-pin power connector, protection class 1
Power consumption Max. Power consumption: 90 Watt (winding operation)
When playing: 16 watts
Standby: 4 watts

Dimensions

480 mm x 520 mm x 200 mm (W x H x D)

Removable wooden side panels for installation in 19 "rack

Weight 27.5 Kg

Best Sirs,

Bob